Concealed Connections and Building Regulations

[stellafella71]

I had building control around to sign off the first fix electrics in my kitchen. I've extended the ring circuit and will need to connect it in to the existing supply. I was going to use 30A junction boxes which will be located in the ceiling/ floor void but aparently, according to the men who know, junction boxes are not considered to be "permanent joints" and shouldn't be used in places that are inaccessible (even though I said I could get to them from the floor above). They said I needed to use a crimped connection in a junction box. Fair enough but what exactly are they? Will I need a special crimping tool as well now? I can't find anything out about them online- any clues?

Thanks.

 

[TicklyT]

You will need a ratchet crimping tool, crimps and something to put the joint in.

http://www.screwfix.com/app/sfd/cat/pro.jsp?id=60547&ts=43473
http://www.screwfix.com/app/sfd/cat/pro.jsp?id=75317&ts=43514#
http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=A331811&ts=43426&id=46538

Some have suggested an in-line 'splice' using staggered crimps and covered with heatshrink sleeving, but I think the jury is still out on that one.

 

[Adam_151]

That tool doesn't appear to be for insulated lugs...

 

[stellafella71]

Thanks for that. At least now if I know what they look like I can point and say "One of them".

Cheers.

 

[Pensdown]

As Adam has said, this is the crimper you need, not the one linked above.

http://www.tlc-direct.co.uk/Products/DVDHCR15.html

...and the choc boxes are an excellent enclosure for your joint.

 

[TicklyT]

Oops


Sorry

 

[CallEdsFirst]

How about one of these?

http://www.cabac.com.au/ims_docs/HT131-C/HT131-C_FULLSIZE.jpg

Or:

http://www.thecrimpcompany.com/scpro/crimp/products/productsmoredetails.asp?id=4882

 

[Lectrician]

How about one of these?

http://www.cabac.com.au/ims_docs/HT131-C/HT131-C_FULLSIZE.jpg

Or:

http://www.thecrimpcompany.com/scpro/crimp/products/productsmoredetails.asp?id=4882[/QUOTE]

Hydraulic? Living in days gone by? Everyones using battery ones these days

 

[FLM]

http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=A331811&ts=43426&id=46538

If you're using this chocbox can you get away with using standard terminal blocks? (e.g. http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=A331811&ts=67566&id=29660)

 

[securespark]

They're still a screwed joint and still need to be accessible...

 

[Pensdown]

How about one of these?

http://www.cabac.com.au/ims_docs/HT131-C/HT131-C_FULLSIZE.jpg

Or:

http://www.thecrimpcompany.com/scpro/crimp/products/productsmoredetails.asp?id=4882[/QUOTE]

Hydraulic? Living in days gone by? Everyones using battery ones these days

I'm still saving up for one of those........

 

[barclay55]

So following this thread if I'm crimp jointing 2.5 T&E I need to use blue insulated butts? Crimp insulation colours relate to cable sizes hence their own rated currents , yes?

So if I'm replacing an 'old' (frowned upon) screw terminal junction box with old cable colours, I join:

red - blue butt - red
yellow/green sleeve - blue butt - yellow/ green sleeve
black - blue butt - black

or making a new joint with new cable colours I join:

brown - blue butt - brown
yellow/green sleeve - blue butt - yellow/ green sleeve
blue - blue butt - blue

or if I use an allowed mix of old and new cable colours then the result is even more confusing. (Its too late at night to do the colours for that !). The new cable brown phase (with blue butt, its own neutral colour) seems especially crass.

Is this all correct?
or have I just been seeing too many rainbows lately?

 

[davy_owen_88]

You should use a red butt crimp for the earth conductor. Remember to sleeve all the earth conductors with green & yellow sleeving.

 

[CallEdsFirst]

Oh thats really gonna confuse things a little more!

"I'd like to return this cable, I ordered 2.5mm but its only got a 1.5 earth!"

In advance of that, the earth in Twin & Earth is one size below the main cores, until you start getting to the bigger sizes, hence why you need a red crimp between the two sleeved earths and a blue on the live and neutral.

 

[barclay55]

Thank you Davy Owen and Call Eds.

Yes of course sleeve the bare earths.

I'm just surprised at the 'fixed' colour of butt insulations.

So latest rules have:
phase earth neutral joints not in a junction box,
but with two blue butts and one red butt in a box?
Ok then, so be it.

A bit of tape of the appropriate indicative colour over the butt insulation would still help though? In the same reasoning as brown tape or sleeving over blue when switch wiring?

ps
I take it a good crimp joint with the correct butt will withstand a lot more current than the cable its designed for, so the crimp doesn't become a fuse? Is there a BS for crimps?